Glossary
VXI-MXI User Manual Glossary-10 © National Instruments Corporation
SMB Sub-miniature BNC; a miniature connector for coaxial cable connections.
Soft Reset Occurs when the RESET bit in the VXIbus Control Register of the
VXI-MXI is set. A soft reset clears signals that are asserted by bits in the
configuration registers but does not clear configuration information stored
in the configuration registers.
Start/Stop Protocol A one-line, multiple-device protocol which can be sourced only by the
VXI Slot 0 device and sensed by any other device on the VXI backplane.
Statically A device whose logical address cannot be set through software; that is, it
Configured Device is not dynamically configurable. The VXI-MXI is a statically configured
device.
Status/ID A value returned during an IACK cycle. In VME, usually an 8-bit value
which is either a status/data value or a vector/ID value used by the
processor to determine the source. In VXI, a 16-bit value used as a data;
the lower 8 bits form the VXI logical address of the interrupting device
and the upper 8 bits specify the reason for interrupting.
Supervisory Access One of the defined types of VMEbus data transfers; indicated by certain
address modifier codes.
Synchronous A communications system that follows the command/response cycle
Communications model. In this model, a device issues a command to another device; the
second device executes the command and then returns a response.
Synchronous commands are executed in the order they are received.
Synchronous The most basic trigger protocol, simply a pulse of a minimum duration on
Protocol any one of the trigger lines.
SYSFAIL* System Fail; a signal that indicates when a failure has occurred in the
system; can be generated by any board in the system.
SYSRESET* System Reset; a signal that indicates a system reset or power-up condition.
System Controller See MXIbus System Controller, VXIbus System Controller.
System Hierarchy The tree structure of the Commander/Servant relationships of all devices
in the system at a given time. In the VXIbus structure, each Servant has a
Commander. A Commander can in turn be a Servant to another
Commander.
T
Terminators Also called terminating networks; devices located at the ends of a MXIbus
daisy-chain that are used to minimize reflections and bias signals to their
unasserted states.